At present, there are known most various structures of shape-stranded ropes, from which variety two groups can be discriminated, the first group including shape-stranded ropes wherein the strands have wires of round cross-section wound about the core (see, for example, the DT Patents Nos. 567,004 and 830,015; the U.S. Pat. No. 3,457,718; the SU Inventor's Certificate No. 500,305), while the second group includes shape-stranded ropes wherein the strands have wires of shaped cross-section wound about the core (see, for example, the DT Pat. No. 656,123; the U.S. Pat. No. 2,122,911, etc.).
However, the ropes of the first group have drawbacks arising mainly from this very round cross-section of the wire, of which the major ones are the relatively low degree of the filling of the cross-sectional area with the rope material, the ribbed external surface of the strands, the inadequate wearability and structural density of the strands.
The known methods of manufacturing such ropes are based on twisting round wires into strands by winding them without practically altering their profile in at least one layer about a core with a sheathing of a soft or deformable material, compacting the strands into a shaped profile and twining the strands into the rope.
The strands of the ropes of the second group, as compared with those of the ropes of the first group, have a more smooth peripheral surface and a higher structural density. However, these shape-stranded ropes neither are free from drawbacks resulting from the very structure of the strands requiring for their formation wires of a sophisticated initial profile of a relatively high bending rigidity. The sophisticated and interdependent initial profiles of the wires put strict requirements as to the manufacture, assembling and indexing of the wires relative to one another while a strand is being formed and shaped, which complicates significantly the entire process of manufacturing shape-stranded ropes.
Thus, the hitherto known methods of manufacturing shape stranded ropes do not provide for combining in the same rope the smooth peripheral surface of the strands, the high structural density, the high degree of the filling of the cross-section of the strand with the rope material, the high wearability, strength and flexibility.